Working with track motion
by Gary Rebholz
The Vegas™ Pro Track Motion tool enables you to manipulate the size and position of any track in your project. For instance, say you want to create a picture-in-picture effect where one stream of video sits in a small box within the main stream. Such an effect is easy to create in Vegas Pro software with the Track Motion tool. In this article we'll explore the tool and learn what you can do with it.
To start, let's create that picture-in-picture effect that I mentioned. Let's say you're working with two waterfall clips: You'll use a clip called Long as your main video and one called Close as the inset video.
First, add your main video clip, Long, to your Vegas Pro timeline. This will be the video that plays full screen. Next choose Insert | Video Track to add a new track to the top of your track list. Add your Close clip to the new track and position the event that holds it so that it sits directly above the event on the other video track that holds Long as I've done in Figure 1.
I'm going to simplify this discussion by assuming from here on out that your project looks just like mine in Figure 1. So, you have only two tracks in your project as I do.
Click to place your cursor within the Close event on track 1 and then look at the Video Preview window. Because Vegas Pro software works from the top down with video tracks, you can only see the clip that sits on the top track. It's like laying one piece of paper over another. If those sheets of paper are exactly the same size, you'll only see the top one even though you know there's another sheet underneath.
But these are not sheets of paper; these are video events on your timeline. And that means that you can manipulate the video for all kinds of effects. In this case, we want to make the video in the top track smaller so that it sits as an inset within the video on the bottom track. And this is exactly where the Track Motion tool comes into play.
To access the Track Motion tool for any video track, click the Track Motion button for that track. Every video track in your project contains a Track Motion button in its track header and I've highlighted the one for track 1 in Figure 2.
Since the video you want to resize sits on track 1, click the Track Motion button for track 1. This opens the Track Motion window, shown in Figure 3.
If you need to, resize and reposition the Track Motion window so that you can see it and the Preview window simultaneously. That way you'll be able to see the results of the changes you make as soon as you make them. Keep in mind that the Track Motion window is moveable and dockable, so you can place it wherever you want to on your screen or on a second monitor if you have one.
There are a lot of controls and buttons and text fields in this window, but it's really not very mystifying at all and you'll see just how easy it is to use the Track Motion window as we work along. The best way to learn what each of these controls does is to start using the tool, so let's make some changes.
The main area of the Track Motion window holds the position box. This box represents the size and shape of the track's output. You'll notice that the position box matches the aspect ratio of your project. The values in the Properties section to the left of the position box give you, for the most part, numerical values for whatever you do in the position box.
So, for instance, look back at Figure 3. Notice that my position box has a widescreen shape. That's because I've set my project up with NTSC HDV values. Now look at the Position properties. The X and Y attributes are both 0 meaning the position box (and thus the track's video output) has not been offset from its natural position. The Width and Height values reflect the HDV property settings that I've assigned to my project.
Now, point to the lower-right-hand corner of the position box. When you do, a circle appears over that corner. When you see that circle, drag the corner point toward the middle of the position box. Watch the Video Preview window. As you drag, you can see that the video output of track one is shrinking to match the shrinking size of the position box. Make the position box small enough that its edges touch the circle within it. (We'll talk about that circle shortly.)
Now look at the Width and Height values again and you can see the exact size of the position box and thus the track's video output. So, you see that changing the position box changes the numerical values too. And it works the other way as well. If you know the exact size you want the track's output to be, you can enter it into the text fields. Click the current value in the Width field. You can type a new value in or use the arrow controls to change the setting. For now, type 600 into the field and press the Tab key to make the change.
When you change the Width, you see that first, the Height value also changed in order to maintain the box's proportions and second, the position box has been changed to reflect the numbers. So, you can work either visually with the position box, or by the numbers with the property fields.
Now let's make a couple other adjustments. Drag the position box to the upper left so that it sits toward the top left of the Video Preview window. When you drag the position box, make sure to click a blank spot within the box. As you'll see, clicking the circle or the hollow dot can cause other things to happen.
Let's take a look at some of the buttons at the top of the Track Motion window. We'll start at the right and move our way left. The first two buttons on the right, the Prevent Scaling (X) and Prevent Scaling (Y) buttons protect you from accidentally resizing your video when you're working with the position box. For example, say you want to make the box narrower, but not change the height. Click the Prevent Scaling (Y) button. Now point to any corner and resize the box. It doesn't matter how far up or down you drag the corner, you cannot change the box's height. Of course, the Prevent Scaling (X) button disables your ability to change the width of the position box.
Click the Undo button in the main Vegas Pro toolbar to undo the change you just made. Click the Prevent Scaling (Y) button to turn it off.
The Scale About Center button is on by default. Drag the position box's lower-right-hand corner again to resize the box. Notice that any move you make to the point you're dragging is matched in the opposite direction by the opposite corner of the box. The box's center point remains fixed. Click the Scale About Center button to turn it off and resize the box again. Now the center of the box moves and the opposite point from the one you're moving remains anchored to its position. Click the Scale About Center button again to turn it back on.
Click the Lock Aspect Ratio button and resize the box another time. Notice that now you can change the aspect ratio of the box freely. In the Video Preview window you can see that this causes distortion in the video as it gets squeezed or stretched beyond its normal shape. Click the Lock Aspect Ratio button again to turn it back on.
Next, the Prevent Movement (X) and Prevent Movement (Y) buttons do just what their names imply they do. Click the Prevent Movement (Y) button and try to move the box up and down. With this button activated, you can't move it vertically. This can be a great help when you want to move the box from side to side but want to ensure that its vertical position remains the same. Click the Prevent Movement (Y) button to turn it off. Of course, the Prevent Movement (X) button restricts horizontal movement in the same way.
Right-click the position box. Here you have a number of options including several that will restore the position box to default values. Choose Restore Box from the menu. This sets the position box back to its normal settings. Make the box smaller and drag it into the upper-left-hand corner of the preview area again.
You can also rotate the box. To do so, drag the large circle within the box. Rotate the box so the video tilts just a little bit. And, as usual, the rotation is reflected in the properties area under the Orientation heading.
There are several more controls available here, but this gives you a good idea of how this tool works. Notice that there is a keyframe controller area at the bottom of the window. Select the 2D Shadow checkbox to add a shadow to the video on the insert track as I have in Figure 4.
Of course, there's a lot more you can do with the keyframe controller area. Further, you can also work with Track Motion in three-dimensional space. But I'll have to leave those discussions for a future article. For now, you know enough about track motion to start using it. Don't be afraid to experiment with it and see what you can come up with.
Tune in again next month for a continuation of our discussion of track motion. If you want to see me walk through the steps I've outlined here and view several other training videos, check out the Les Stroud hosted series of videos and the other free training videos available. There, you'll also find other valuable training resources like our Seminar Series packages and information on the Vegas Pro Certification.
Gary Rebholz, is the training manager for Sony Creative Software. Gary produces the popular Seminar Series training packages for Vegas Pro, ACID Pro, and Sound Forge software. He is also co-author of the book Digital Video and Audio Production. Gary has conducted countless hands-on classes in the Sony Creative Software training center, as well as at tradeshows such as the National Association of Broadcasters show.